You play as a citizen who wakes in the canals behind his apartment. You don't remember how you got there, but the empty bottles around you give you a good idea of what happened. You aren't sure how to get back home, but sitting in the mud won't help. The canals of City 17 are known to be infested with headcrabs, and headcrabs mean zombies. You know that the Underground Railroad is nearby, and probably willing to help get you back to your home safely. Unfortunately for you, City 17 is about to have a visitor who is going to make your trip through the Canals just that much more difficult than they were already going to be. You are about to be fighting through a lot more than just a few zombies.